Taxes (Schedule of Gross Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning Balance	$ 38,877	$ 34,709	$ 31,789
Additions based on tax positions related to the current year	2,709	4,168	2,920
Additions for tax positions of prior years	2,979
Reductions as a result of lapses in the statute of limitations	(37,110)
Ending Balance	$ 7,455	$ 38,877	$ 34,709